Changes

: [[Wave Speed]] is measured in [[metres per Second|metres per second]].

<math>v = \tfracdfrac{x}{t}</math> 

 v = '''Wave Speed''' x = distance traveled t = time taken to travel ====Equation 2==== <math>v = f \lambda</math> <math>v = f \times \lambda</math> Where:  v = '''Wave Speed''' f = [[frequency]] of the [[wave]] λ = [[wavelength]] of the [[wave]] ==Key Stage 4=====Meaning===[[Wave Speed]] is how quickly a [[wave]] travels through a [[medium]]. ===About Wave Speed===: '''Wave speed''' is a [[scalar]] because it has [[magnitude]] only.: The [[SI Unit]] of [[Wave Speed|wave speed]] is [[Metres per Second|metres per second]].: The '''wave speed''' states how quickly [[energy]] and [[information]] can be transferred by a [[wave]].: '''Wave speed''' can change depending on the [[medium]] the [[wave]] is travelling through.: When a [[wave]] enters a new [[medium]] it will change in [[speed]]. ===Equation=======Equation 1====<math>v = \dfrac{x}{t}</math> Where v = '''Wave Speed''' x = distance traveled: t = time taken to travel

:<math>v = f \lambda</math>:<math>v = f \times \lambda</math>

 v = '''Wave Speed''' f = [[frequency]] of the [[wave]] λ = [[wavelength]] of the [[wave]] ===Example Calculations=== ====Finding Wave Speed from Distance Travelled and Time Taken===={| class="wikitable"| style="height: 20px; width:300px; text-align:center;" |A scientist [[observe]]s a [[wave]] in a ripple tank. The length of the tank is 0.75m and it takes the [[wave]] 1.2 seconds to get from one end of the tank to the other. Calculate the '''wave speed''' of the [[wave]] correct to two [[Significant Figures|significant figures]].| style="height:20px; width:300px; text-align:center;" |A surfer wants to know how fast the [[wave]]s are travelling on a windy day. The surfer observes a [[wave]] takes 15 [[second]]s to travel between two buoys. The surfer knows the distance between the buoys is 63m. Calculate the [[speed]] of the [[wave]] correct to two [[Significant Figures|significant figures]].|-| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities''' x = 0.75m t = 1.2s| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities''' x = 63m t = 15s|-| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].''' <math>v = \dfrac{x}{t}</math> <math>v = \dfrac{0.75}{1.2}</math> <math>v = 0.625m/s</math> <math>v \approx 0.63m/s</math>| style= "height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].''' <math>v = \dfrac{x}{t}</math> <math>v = \dfrac{63}{15}</math> <math>v = 4.2m/s</math>|} ====Finding Wave Speedfrom Wavelength and Frequency===={| class="wikitable"| style="height:20px; width:300px; text-align:center;" |A [[Water Wave|water wave]] has a [[wavelength]] of 1.6m and a frequency of 1.5Hz. Calculate the [[speed]] of the [[wave]].| style="height:20px; width:300px; text-align:center;" |A ray of [[ultraviolet]] [[light]] with a [[frequency]] of 7.5x10¹⁴Hz and [[wavelength]] of 0.30μm in an [[Optical Fibre|optical fibre]]. Calculate the [[speed]] of the [[wave]] through that [[Optical Fibre|optical fibre]] correct to 2 [[Significant Figures|significant figures]].|-| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities''' f = 1.5Hz λ = 1.6m| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities''' f = 7.5x10¹⁴Hz λ = 0.30μm = 0.30x10^-6m|-| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].''' <math>v = f \lambda</math> <math>v = 1.5 \times 1.6</math> <math>v = 2.4m/s</math> | style="height: 20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].''' <math>v = f \lambda</math> <math>v = 7.5 \times 10^14 \times 0.30 \times 10^{-6}</math> <math>v = 225000000m/s</math> <math>v \approx 2.3 \times 10^8 m/s</math>|} ====Finding Wavelength using Wave Speed and Frequency==== {| class="wikitable"| style="height:20px; width: 300px; text-align:center;" |A [[wave]] with [[frequency]] 700Hz travels at a [[speed]] of 340m/s. Calculate the [[wavelength]] of the [[wave]]correct to two [[Significant Figures|significant figures]].| style="height: λ 20px; width: 300px; text-align:center;" |A 630MHz [[radiowave]] travels at 300,000,000m/s in a [[vacuum]]. Calculate the [[wavelength]] of this [[radiowave]] correct to two [[Significant Figures|significant figures]].|-| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities''' f = 700Hz v = 340m/s| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities''' f = 630MHz = 630x10⁶Hz v = 300,000,000m/s = 3x10⁸m/s|-| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>v = f \lambda</math> <math>340 = 700 \times \lambda</math> | style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>v = f \lambda</math> <math>3 \times 10^8 = 630 \times 10^6 \times \lambda</math>|-| style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math> \lambda = \dfrac{340}{700}</math> <math> \lambda = 0.48571m</math> <math> \lambda \approx 0.48m</math> | style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math> \lambda = \dfrac{630 \times 10^6}{3 \times 10^8}</math> <math> \lambda = 2.1m</math>|} ====Finding Frequency using Wave Speed and Wavelength==== {| class="wikitable"| style="height:20px; width:300px; text-align:center;" |A [[microwave]] travelling at a speed of 3.0x10⁸m/s has a [[wavelength]] of 0.051m. Calculate the [[frequency]] of the [[wave]] correct to two [[Significant Figures|significant figures]].| style= "height:20px; width:300px; text-align:center;" |An [[ultrasound]] [[wave]] of [[wavelength]] 0.125m passes through an [[Iron]] block at a [[speed]] of 5000m/s. Calculate the [[frequency]] of the [[wave]] correct to two [[Significant Figures|significant figures]].|-| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities''' v = 3.0x10⁸m/s λ = 0.051m| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities''' v = 5000m/s λ = 0.125m|-| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>v = f \lambda</math> <math>3.0 \times 10^8 = f \times 0.051</math>| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>v = f \lambda</math> <math>5000 = f \times 0.125</math>|-| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math> f = \dfrac{3.0 \times 10^8}{0.051}</math> <math> f = 5882352941Hz</math> <math> f \approx 5900000000Hz</math>| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math> f = \dfrac{5000}{0.125}</math> <math> f = 40000Hz</math>|} ===References=======AQA==== :[https://www.amazon.co.uk/gp/product/019835939X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=019835939X&linkCode=as2&tag=nrjc-21&linkId=57e96876985fc39b1a3d8a3e3dc238b6 ''Wave speed, pages 176-177, 186-187, 190-191, GCSE Physics; Third Edition, Oxford University Press, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe10425 ''Wave speed, pages 220, 221, GCSE Combined Science; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1471851362/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851362&linkCode=as2&tag=nrjc-21&linkId=7d78d70a2044ee9982dae010c94af92a ''Wave speed, pages 258, GCSE Combined Science Trilogy 2, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/178294558X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294558X&linkCode=as2&tag=nrjc-21&linkId=f0dfb66dafcb0c6e9449e7b1a4ae1ac499 ''Wave speed, pages 73, 74, 76, GCSE Physics; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1471851362/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851362&linkCode=as2&tag=nrjc-21&linkId=7d78d70a2044ee9982dae010c94af92a ''Wave speed; Electromagnetic waves, pages 262, GCSE Combined Science Trilogy 2, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/1471851370/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851370&linkCode=as2&tag=nrjc-21&linkId=01c69b0ae058f809cf636033e6ba793e ''Wave speed; measurement of, pages 185-6, GCSE Physics, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/1471851362/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851362&linkCode=as2&tag=nrjc-21&linkId=7d78d70a2044ee9982dae010c94af92a ''Wave speed; Measurement of, pages 259, GCSE Combined Science Trilogy 2, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/1471851370/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851370&linkCode=as2&tag=nrjc-21&linkId=01c69b0ae058f809cf636033e6ba793e ''Waves speed, page 184, GCSE Physics, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe10436 ====OCR====:[https://www.amazon.co.uk/gp/product/1782945695/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945695&linkCode=as2&tag=nrjc-21&linkId=ceafcc80bcad6b6754ee97a0c7ceea53 ''Wave speed, pages 187, 188, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR '']